An issue of growing importance at airfields and airports is the control and management of surface movement of aircraft, vehicles and foot traffic. As more airplanes are filling the skies, there has been a burgeoning burden on ground crews and the control tower in managing the increasingly congested traffic on runways, taxiways, loading and standby areas. Of particular concern is the rising incidences of potential runway incursions occurring between airplanes and, additionally, with ground vehicles. A runway incursion occurs whenever there is an event that creates a possible collision between an aircraft and another aircraft, vehicle, or object on the runway and is mandatorily reported to the FAA.
Airlines have taken the initiative to reduce air-traffic congestion or runway collisions by using enhanced communications gear and revised landing approaches. However approaches to runways, taxiways, arrival/departure gates and other locations of interests are primarily navigated by signals from ground crew, visual feedback and control tower instructions. In varying inclement weather, night conditions, or congested airports, there is an increased concern that visually guided navigation of the runways, taxiways, arrival/departure gates can be compromised. Moreover, it is not unheard of for pilots to become disorientated at an unfamiliar airport and guide their airplane to the wrong terminal or even off a taxiway.
There have been several efforts underway to alleviate airport surface movement problems. On such effort is the ASDE-X program (Airport Surface Detection Equipment) by Raytheon which uses distributed multilateration sensors coupled with a centralized X-band radar. The Raytheon system is a positional system and the centrally located X-band radar is used to track surface objects that do not have a multilateration responsive transponder.
Similarly, Transtech of Windsor, Conn. has devised a surface movement radar system using distributed millimeter wave sensors with a centralized X-band radar and optical identification sensors, to generate a real time situational map of the airfield. However, as alluded above, the Raytheon and Transtech systems require a large and expensive centralized X-band radar and are not capable of providing accurate orientation of a detected aircraft or wheel positioning.
Therefore, there has been a long standing need in the airport community for systems and methods which provide a more accurate airplane or target detection, classification and tracking.